1. Field of the Invention
The present invention relates generally to an air conditioner, and more particularly, to an air conditioner that utilizes two refrigerants and an intermediate unit to provide heat exchange between the two refrigerants.
2. Description of Related Art
Generally, an air conditioner is an apparatus for heating and cooling an indoor space using a refrigerating cycle. The air conditioner generally includes components for performing a refrigerating cycle, such as an indoor heat exchanger mounted indoors for performing heat exchange with indoor air, a compressor for compressing a refrigerant, an outdoor heat exchanger mounted outdoors for performing heat exchange with outdoor air, and an expansion valve for reducing the pressure of the refrigerant to expand the refrigerant.
Recently, a heat-pump type air conditioner has been developed that is capable of performing both heating and cooling operations. The heat-pump type air conditioner includes a compressor for compressing a gaseous, low-temperature, low-pressure refrigerant into a high-temperature, high-pressure refrigerant, a condenser (an outdoor heat exchanger for the cooling operation; an indoor heat exchanger for the heating operation) for condensing the refrigerant discharged from the compressor, an expansion valve for expanding the refrigerant condensed by the condenser, i.e., the liquid refrigerant, an evaporator (an indoor heat exchanger for the cooling operation; an outdoor heat exchanger for the heating operation) for evaporating the refrigerant introduced from the expansion valve, and a four-way valve for changing the flow direction of the  refrigerant according to the cooling or heating operation. The compressor, the outdoor heat exchanger, and the four-way valve are mounted in an outdoor unit, whereas the indoor heat exchanger is mounted in an indoor unit. The indoor unit and the outdoor unit are connected with each other via a refrigerant pipe.
Another conventional air conditioners is a multi-type air conditioner constructed in a structure in which a refrigerant is supplied, using a plurality of indoor units and an outdoor unit, to individually heat and cool indoor spaces where the indoor units are installed.
In the conventional multi-type air conditioner, however, the outdoor unit has only a single heat exchange mode of the refrigerant. As a result, it is not possible to use various heat exchange modes. Also, the outdoor unit of the conventional air conditioner is constructed in a structure in which the compressor is mounted in the outdoor unit. In other words, the compressor is not separated from the outdoor unit. As a result, there is a strong possibility of the outdoor unit falling due to its own weight when the outdoor unit is installed in a multistoried building. In addition, it is difficult to repair or replace the outdoor unit or the compressor with a new one. Furthermore, the installation of the outdoor unit is restricted.